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Nov. 27, 1934. H. s. YOUNG 1,981,979

RAILWAY TRAFFIC CONTROLLING APPARATUS I Filed Sept. 25, 1931 2 Sheets-Sheet l A5TP 111N2 538? Time Elemeni Del/we [Z r INVENTOR.

g .s.) aun BX Glam I M ATTORNEY.

Nov. 27, 1934.

H. s. YOUNG 1,981,979

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Sept. 25, 1951 2 Sheets-Shet 2 AST INVENTOR. [1,5,3 H bun H- L ATTORNEY.

Patented Nov. 27, 1934 UNITED STATES RAILWAY TRAFFIC CONTROLLING APPARATUS Application September 25, 1931, Serial No. 565,086

12 Claims.

My invention relates to railway trafiic controlling apparatus, and particularly to apparatus for governing trafiic at points where two or more tracks intersect or converge.

I will describe one form of my invention, and will then point out the novel features thereof in claims.

The accompanying drawings, Figs. 1 and 2 when placed together with Fig. 1 on the left, con stitute a diagrammatic view showing one form of my invention when applied to a layout wherein two tracks cross each other, and a third and fourth track branch from the intersecting tracks.

Referring to Figs. 1 and 2, the reference characters a and b designate the tracks of two railways that intersect at the point 25. The reference character 0 designates a siding or transfer track branching from the track 72, while at is a passing siding for the track a. The track a is divided by the usual insulated rail joints 10 into track sections AlT, 1T and ABT of which AlT and A31? may be termed approach sections and 1T a crossing track section. The track b is divided in a similar manner into the track sections A lT, 4T, EST and A5T of which 4T is a crossing track section and A51, B5T and A4? are approach track sections. The traiiic rails of the sections 1T and 4T at the crossing 25 are insulated from each other by the usual insulated joints and are made electrically continuous by conductors around the insulated joints in the customary manner as will be readily observed by an inspection of Fig. 2. The track section 135T is preferably made only a few rails in length, say one hundred feet.

Each track section of the tracks a and b is provided with the conventional track circuit consisting of a source of current such as a battery connected across the trafiic rails adjacent one end of the section. Connected across the trafiic rails adjacent the opposite end is a trackrelay designated by the refer-ence character R plus a prefix corresponding to the track section. It will thus be seen that each track section is equipped with a track circuit that includes a track battery 11, a track relay R and the traffic rails of the section in series. A track re eater relay ASTP is controlled by a circuit that includes the front contacts of the armatures 103 and 166 of the track relay BSTR and the front contacts of the armatures 104 and 105 of the track relay AB'IR as will be readily understood by an inspection of Fig. 2.

Energy for operating the apparatus of my invention may be obtained from any convenient source either alternating current or direct current but which is not shown in the figures. For

different points in the figures certain of the ar-- this description-I shall consider the source to be direct current and. that the'relays are direct cur-- rent relays. Throughout the figures the positive terminal of the source of current is designated by the reference character BL and the negative terminal by the reference character CL.

Traffic from the left to the right over the track a I shall term eastbound trafiic, and traffic from the right to the left over track a I shall term westbound traliic. Traffic moving from the left tothe right on the track I) I shall term northbound while traflic in the opposite, direction on the track b will be spoken of as southbound. While the siding d and the transfer track 0 are shown in the figures as branching from the track sections 1T and A51, respectively, it will be understood that these siding. tracks may extend from other track sections, and also that there may be additional sidings without departing from the spirit and scope of my invention. The track layout illustrated in Figs. 1 and 2 will serve to illustrate the principle of my invention.

.In order to simplify the figures, so that they maybe more readily understood, I shall show at matures. ior the different relays at locations not adjacent to the relay. In each instance this armature will be given a reference character corresponding to the relay that operates that armature plus adistinguishing exponent and the armature will be shown in the position corresponding to the normal condition of the relay. For example, in Fig. 1 the armature designated by the reference character A3TR is operated by the track relay A3TR ofFig. 2 and the armature is shown in engagement with its front contact inasmuch as therelay A3TR is normally energized. The switch A1 leading to the passing siding d has connected to it a circuit controller L as is indicated by a dotted line. In accordance with standard practice this circuit controller is operated between its two circuit controlling po sitions in step with the switch A1 as it is set for the track a or for the siding d. At certain points in the drawings there are shown contacts of the controller L which are designated by the reference character L plus a distinguishing exponent. These contacts are shown in the position that corresponds to the position occupied by the controller L when the switch A1 is set for the track a.

Eastbound traiiic on the track a is governed by the wayside signals 1 and 6, and westbound trafiic by the signals 3 and 7. Northbound trafilc on track I) is governed by the signals 4 and 8, while the southbound trafiic is governed by signals 5 and 9. The signal 2 governs eastbound trafiic moving from the siding d. Signal 5 is provided with two mechanisms A and B. Signal A5 governs through southbound traffic while signal B5 is a special slow speed signal to govern a train that has stopped'jo do switching in the vicinity of the transfer j track c as will be more fully explained hereinafter. These wayside signals may be of any. standard type in general use and are here indicated by symbols only. The signals 6, '7, 8 and 9 act as distant signals for the associated signals 1, 3, 4 and 5, respectively, and as these distant signals form no part of my invention the means for their control is omitted from the figures and these signals will not be further referred to, The signals 1, 2, 3, 4 and 5 each govern traflic over the crossing 25 and each is capable of assuming either a clear or a stop indication. As the operating circuits for these wayside signals I nnno part of my invention, they are omitte the figures for the sake of clearness. It"? i 'e understood that the operating circuits for each signal are governed by a signal controlling relay, to be shortly pointed out, in such a manner that when the relay is energized the signal is cleared, while as long as the relay is deenergizeql the corresponding signal is set at stop.

The signal controlling relays governing the operation of the signals are designated by the reference character H plus a prefix corresponding to the signal. The controlling circuit for the signal controlling relay 1H, that governs the operation, of signal 1, starts at positive terminal BL and includes the front contact of armature 14 of the track relay lTR for track section 1T, front contact of armature 15 of track relay 4TR. for section 4T, wire 16, normally closed contact 17 of a manually controlled time release b to be referred to later, normally closed contact 18 of a second manually controlled time release a front contact of armature 19 of a route locking relay 45LS associated with north and southbound traffic as will be described later, wire 20, contact L of the switch circuit controller L, back contact of armature 22 of the signal controlling relay 2I-I, back contact of armature 38 of a stick relay 38 associated with signal 3 and to be described later, back contact of armature 3H of the signal controlling relay 3H, front contact of armature A3TR of the track relay ABTR, back contact of armature 27 of track relay AlTR for the approach track section A1T, winding of relay 1H and to the negative terminal CL. As this circuit is normally open at the back contact of armature 27 of the track relay AlTR for the approach track section AlT, it follows that under normal conditions an eastbound train upon entering the approach section AlT and shunting the track relay AlTR will cause the signal 1 to be cleared. It is also to be noted that the circuit for relay 111 is held open at armature 3H Whenever the signal controlling relay for the opposing signal 3 is energized to clear its signal, also, when either crossing track section IT or 4T is shunted, or when the route locking relay 4-5LS is deenergized so that armature 19 is down.

The relay 2H that governs the operation of the signal 2 is controlled by the same circuit above traced for the relay 111 from positive terminal BL up to the contact L21 of the switch circuit controller L, hence, when the switch A1 is set for the siding d and the contact L21 moved to its lower position as shown in Fig. 1, the Circuit extends along wire 28, back contact of armature 29 of relay 1H, back contact of armature 3H of relay 3H, front contact of armature A3TR of the track relay ABTR, winding of relay 2H and to the negative terminal CL. It follows that whenever the switch Al is reversed for a traflic movement from the siding d the relay 21-1 is energized and the signal 2 is cleared if the remaining apparatus occupies its normal position. It is to be noted especially that the relay 2H cannot be picked up if either of the crossing track sections IT or 4T are occupied, or if the route locking relay 45LS is deenergized.

The relay 31-1 that governs the westbound signal 3 has a circuit that starts at positive terminal BL and extends along the same circuit as traced for the relay 1H up to the back contact of armature 22 of relay 2H, thence by wire 32, back contact of armature 18 of a stick relay 1S associated with signal 1 as will be described later, back contact 1H of relay 1H, front contact of armature AlTR of the track relay AlTR, back contact of armature 36 of track relay ASTR for the approach track section A3T, winding of relay 3H and to the negative terminal CL. As this circuit is normally completed except at the back contact of armature 36 of relay A3TR, it follows that under normal conditions a westbound train entering the approach track section A3T will cause relay 31-1 to become energized to clear the signal 3. It will be I noted in connection with this circuit for the relay 311 that it is held open whenever a signal controlling relay for the opposing signals 1 or 2 is energized. Also that the circuit is controlled by the crossing track sections 1T and 4T and by the 1 route locking relay 4-5LS.

The circuit to the signal controlling relay 4H governing the operation of the signal 4 is the same as that traced for the relay 1H from positive terminal BL upto the wire 16, hence by a I normally closed contact 37 of the time release 12*, normally closed contact 38 of the time release a back contact of armature 39 of relay 31-1, wire 40, back contact of armature 41 of relay 2H, back contact of armature 42 of relay 1H, front contact 1 of armature 43 of a route locking relay 1-.3LS associated with east and westbound trailic as will be described later, a back contact 44 and a checking contact 45 of a time element device STE to be described later, back contact of armature 53 of 1 a stick relay 58 associated with signal 5, back contact of armature B511 back contact of armature A511 front contact of armature A5TP back contact of armature 50 of track relay A4TR for the approach track section A4T, winding of l relay 4H and to the negative terminal CL. As this circuit is normally completed except at the back contact of armature 50 of the track relay for the approach track section A4T, it is to be seen that under normal conditions a northbound 1 train upon entering the approach track section A4T will cause the relay 41-1 to be energized and the signal 4 cleared. In connection with this circuit for the relay 4H it is to be noted that the circuit will be opened when a signal controlling l relay for the opposing signal 5 or for one of the signals 1, 2 or 3 of the crossing road is energized, and that it is controlled by the track sections 1T and 4T, and by the route locking relay 13LS associated with east and westbound traffic. l The relay A5H that governs the operation of the mechanism A of signal 5 is controlled by the same circuit just traced for relay 411 up to the armature 43 of the route locking relay 1--3LS, thence by the wire 51, back contact of armature 1 of the signals 1, 2 or 3 of the crossing road is energized, andit is controlled by the track sections 1'1 and 4T and by the route locking relay 1-3LS.

The relay 85H that governs the special low speed signal B5 is provided with a circuit that is the same as that described for the relay A5H from up to the armature ASTP of the track repeater relay A5TP from which point there extends a circuit network of parallel paths to the winding of the relay 85H. All paths of this network extend from the armature ASTP through the front contact of armature 5TE of the time element device STE from which point one path includes contact L of the switch circuit controller L, front contact of armature A3TR front contact of armature AITR winding of relay B5H and to the negative terminal CL. Another path includes the back contact of armature E5113. and to the winding of the relay B5H. From contact L there is one path that includes the front contact of armature of the stick relay 1S and the armature AI'IR and a second path that includes the armature A3'IR and the front contact of armature 38 of the stick relay 33. As the circuit for the relay B5B is the same as that for the relay A5H up to the circuit network this relay B5I-I can be energized under normal conditions only when a southbound train occupies the section A5T. As each path of the circuit network leading to the relay 35H includes the front contact of the armature 5TE it follows that for the relay B5I-I to be energized to clear the special signal B5 a sufficient time must elapse for the time element device 5TE to function. The operation of the time element device 5TE and of the circuit network for the relay 35H will be more fully pointed out when the operation of the system is described for southbound trafilc.

From the description of the circuits for signal controlling relays, it follows that as a train approaches the crossing on any track a signal controlling relay becomes energized to clear a signal for that train to advance over the crossing. As this signal controlling relay picks up it opens at back contacts the controlling circuit for the signal controlling relay of the opposing signal. It is to be noted, however, that the circuits for the signal controlling relays 4H, A5H and H for the north and south road include backcontacts of armatures 42, 41 and 39 of the relays 1H, 2H and 3H for the east and west road, re spectively, while similar back contacts are not included in the circuits leading to the relays 1H, 2H and 3H. This gives a slight advantage to the relays for the east and west road in the case of trains on each of the crossing roads entering an approach section simultaneously.

For each signal there is provided a stick relay designated by the reference character 8- with a prefix corresponding to the signal. As the cirrsuflicient for an understanding of all. Referring to the stick relay with-signal 3 we find that this relay has an energizing circuit that extends from the positive terminal BL through a back contact of armature 1TB of the track relay lTR, front contact of armature 65 of the relay 3H when that relay is through the back contact of armature Al'I'R of the track relay AITR, back contact of armature 65 and the front contact of its own armature 66. From the foregoing we see that the stick relay 38 is picked up during the interval that the relay 3H remains up after a train shunts the track relay lTR as it passes the signal 3 when the signalcontrolling relay 31-1 is energized. The signalcon trolling relay 3H, as all signal controlling relays of my system, is provided with slow-releasing characteristics that will retain its armature in engagement with its front contacts for a period sufliciently long to permit the stick relay 3S to be picked up after the track relay lTR' has been shunted. With this stick relay 38 once picked up it is retained energized by its stick circuits that are held closed as the westbound train travels through the track sections IT and then moves away from the crossing through the opposing approach track section AlT.

The stick relay 18 associated with the signals 1 and 2 has an energizing circuit similar to that described for relay 3S, and then in addition there is provided a second energizing circuit that includes the back contact of armature 167 of the track relay lTR, back contact of armature 68 of relay 1H and the front contact of thearmature 69 of the relay 2H. Thus this relay 1S becomes energized when a train moves east from the siding d into the track section lT'as well as when an eastbound train advances on the track a past the signal 1' into section IT. The stick circuits for the relay 15 are substantially similar to those describedfor the relay 38, one including the back contact of A3TR and thus the relay 18 is retained energized while an eastboundtrain 38. associated 5 mature 73 of relay B511, and to the winding of relay 55. Thus the stick relay 5S will be energized when a southbound train advances past signal 5 with either relay A525 or B5H energized. The stick circuits for relay 58 are similar to those for relay 3S. One circuit includes the back'contact of armature 4TH, and the second includes the back contact of armature A lTR of the relay A4TR. It follows that each. stick relay will be L of the switch circuit .of relay i-5LS and to picked up as a train advances past the associated signal in a clear'position and will be retained energized until that train has passed over the crossing and has vacated the opposing approach track section. The function of each stick relay will be pointed out when the operation of a system is discussed.

There is provided for each road a route looking circuit and relay. The route locking relay 4-5LS is associated with the east and westbound traffic while the route locking relay 1--3LS is associated with the north and southbound traffic. Referring to the relay 1-3LS, this relay is normally energized by a route locking circuit that starts at the positive terminal BL at the back contact of armature '75 of relay 1H and includes the back contact of armature '76 of relay 2H, back contact of armature 31 wire 78, contact controller L, front contact of armature AlTR' front contact of armature 1TB front contact of armature A3TR to the negative terminal CL. From the wire '78 there branches a normally closed stick circuit through the front contact of the armature 81. From wire 78 there also branches two normally open parallel pickup circuits. One pick-up circuit is through the front contact of armature 18 and the back contact of armature ABTR to the winding of the relay 1-3LS. The second pick-up circuit extends from wire '78 along wire 83, normally open contact 84 of the time release a and wire 85 to the winding of the relay 1-3LS. Still another pick-up circuit for this relay branches from the contact L through the normally open back contact of armature A1TR3 for the track relay AlTR, normally open front contact of armature 3S of stick relay 3S and to the winding of the relay 1-3LS.' Except to point out that the relay l-3LS is retained energized by its stick circuit as long as the three signal controlling relays 11-1, 21-1 and 31-1 are deenergized, the function of this network of circuits associated with the relay 1-3LS will not be taken up in detail until the operation of the system is described.

The route locking relay 45LS associated with north and southbound traffic is provided with a circuit network substantially similar to that described for the relay l--3LS. The relay 4-5LS is normally energized by a circuit that starts at the positive terminal BL at the armature 88 of relay 1351i and includes the back contact of armature 89 of relay A511, back contact of armature 4H of the relay 4H, wire 91, front contact of armature A iTR front contact of armature 4TB, front contact of armature A5TP winding the negative terminal CL. From the wire 91 there branches a stick circuit through the front contact of its own armature 95. Three parallel paths also branch from the wire 91 to the winding of the relay l-5LS by the means of which this relay can be energized. One path includes the front contact 96 of the time release 11*, a second path includes front contact of the armature 4:8 and the back contact of armature A5TP while a third path includes back contact of armature ATR" and the front contact of armature 55 The function of this network of circuits will be pointed out when the operation of thesystem is considered. In addition to this network of circuits just traced for the relay 4-5LS there is also provided a pick-up circuit that extends from positive terminal BL the same as above described up to the wire 91 and then through a front contact of the armature 107 of ous deenergizing to a train on each of the crossing roads entering an approach track section simultaneously. This feature, together with the above-mentioned fact that the circuit for the signal controlling relays of the north and south road is controlled by back contacts of the signal controlling relays of the east and west road, give precedence to the east and westbound trains over north and southbound trains when trains on each road enter an approach track section simultaneously.

Associated with the tracks 12- and c is a time element device or relay 5TE. This time element device may take different forms several of which are well-known in the art, but a preferred form is that of a time element relay wherein circuit contacts are not operated until a predetermined time interval after the energizing circuit for the winding of the relay has The time element device 5TE is provided with a circuit that starts at the positive terminal BL open back contact of the armature 100 of the relay A5TP, and includes wire 101, back contact of armature 102 of the 4S stick relay, winding of the relay 5TE and to the negative terminal CL. Thus, when a southbound train occupies either track section A5T or BET, the circut to the time element relay 5TE. is closed and after a predetermined time interval, which I shall speak of as being five minutes, the armatures 107 and 5TE? are brought into engagement with front contacts while the armatures 44 and 5TE are lifted out of engagement with their back contacts. When this energizing circuit to the winding of relay turn to their normal position.

In describing the operation of the system I shall first assume an eastbound train enters the approach track section AlT at a time when all the other track sections are unoccupied. As the track relay AlTR is shunted the circuit to the relay 111 is closed and that relay is energized to clear the signal 1. As soon as the relay 111 is energized the circuits to the signal controlling relays for the opposing signals 2 and 3 and to each controlling relay of the signals of the crossing road are opened to prevent any of these signals from clearing. As the track relay AlTR is shunted the circuit to the route locking relay 1-3LS is opened at the armature AlTR" and then as soon as relay 1H picks up the stick circuit of relay 1-3LS is opened at the armature '75 and this route locking relay is deenergized to lock out the signal controlling relays for the north and south road at the train advances past the signal 1 into the section 1T and shunts the track relay lTR, the circuit to the relay 111 is opened at the armature 14 and at the end of its slow-release period signal 1 is set at stop. As the train shunts the track relay lTR the energiz-, ing circuit for the stick relay 18 is closed during the release period of the relay ll-I. After relay 1S is once picked up it is retained energized by its stick circuits as long as the eastbound train occupies either track section 1T or A3T. As the relay 1TB. is shunted it closes the normal energizing circuit to the relay 1.3LS at the back contact of the armature 75, but this circuit to the route locking relay is held open at thefrontcontact of armature 1TR of the track relay lTR. or at the front contact of the armature A3TR of the track relay A3TR as long as the eastbound train occupies the track sections IT and A3T, respectively.

As previously pointed out there is provided an energizing circuit to the relay 1-3LS that includes the front contact of the armature 18 of the stick relay 1S and the back contact of the armature A3'IR of the track relay -A3TR. The energizing of the stick relay 1S is accomplished as the eastbound train entered the section IT and then as the eastbound train enters the section A3T and shunts the track relay A3TR the stick relay 18 is retained energized and thus this energizing circuit through armatures 1 5 and A3'JI'R to the relay 13LS is completed and the relay is picked up. That is to say, to energize the route locking relay l3LS requires two steps, the first of which is accomplished as the eastbound train entered the section lT and picked up the stick relay IS. The second step is accomplished as the train subsequently enters the track section A3TR. With relay l-3LS energized a signal for the crossing road can be cleared as soon as the eastbound train vacates the section IT and the track relay lTR becomes energized to close the front contact of the armature 14'.

As noted above the stick relay 18 is held energized through the back contact of the armature A3TR and as the control for the 3H relay for the signal 3 includes the back contact of armature 18 it is apparent that this signal 3 will not be cleared by the eastbound train entering the section A3'I' although as the track relay A3TR is shunted it closes the back contact of armature 36. The stick relay 1S, therefore, serves two functions, first, to complete the first step in the energizing of the route locking relay 13LS, and second, to prevent the clearing of the westbound signal 3 when an eastbound train occupies the approach track section A3T.

As the eastbound train vacates the section AST the second stick circuit for the relay 18 is opened and that relay deenergized. As relay A3TR picks up, the normal circuit for the relay 13LS is closed and thus the apparatus is restored to its normal position. Furthermore, it is to be noted that should an eastbound train enter the approach section All and then back out of that section the relay IE will first be picked up to clear the signal 1 and the route locking will become effective in the manner previously described, but as soon as the train backs out of the section the signal controlling relay IE will Y. become deenergized so that the signal 1 is restored to its stop position and the route locking" is restored to its normal condition.

If, while the eastbound train occupied the approach track section AlT the section A3T should be momentarily shunted, the deenergizing of the track relay ABTR will deenergize the relay 1H and the signal 1 is set at stop, but the stick relay 13 will not become energized and thus the route locking relay l-3LS will not be reenergized. As the front contact of armature 43 is in the contrcl of all signals of the crossing road, the momentary shunting of the section A3T with an eastbound train approaching the signal 1, will not make it possible for a signal on the other road to be cleared.

It will be further observed that a momentary shunting of the section 1T Will not permit the clearing of a signal on the crossing road while the eastbound train is approaching the signal 1. The shunting of the track relay lTR will result in the stick relay is becoming energized and thus close the front contact of armature 18 in the pick-up circuit of the relay l-3LS. This pick-up circuit is, however, still held open at the back contact of armature A3TR of the track relay forthe section A3T. If the shunt on the section IT is but momentary then as soon as it is removed the relay IE will again pick up to clear the signal 1 and to deenergize the stick relay 13. It is to be seen, therefore, that the two subsequent steps required for the release of the route locking insures that a momentary or premature shunting of the track sections in advance of the train will not result in a condition that will permit the clearing of a signal for the crossing road. I

The operation of the apparatus for a westbound train is similar to that described for an eastbound train. The westbound train upon entering the approach section A3T closes the circuit to the relay SE to clear the signal 3 and to open the circuit for the relay 1-3LS at the back contact of the armature 31-1 Stick relay BS is picked up as the train enters the section IT and is held energized'by its stick circuits as long as the westbound train occupies either track section IT or AlT. The route locking relay 13LS is reenergized in two steps, the first being accomplished as the stick relay SS is picked up to close the front contact of armature 3S, and the second step is accomplished when the track relay AlTR is shunted to close the back contact of the armature AITR It is to be noted in connection with westbound traffic that in the event the train moves into the siding d, that when the train has vacated the section IT and the switch A1 is restored to its normal position the normal energizing circuit for the route locking relay 13LS is completed and that relay reenergized.

If a train wishes to advance east from the siding d, the setting of. the switch A1 of the siding the train advances east from the siding d, the

operation of the stick relay 1S and the route locking relay 13LS will be the same as that pointed out in connection with the eastbound train advancing on the main track a.

vI shall next assume that a northbound train enters the track section A4=T at a time when all the other track sections are unoccupied. The shunting of the track relay A4TR completes the circuit to the relay 4H and that relay is energized to clear the signal 4. As the relay 4H picks up the circuit to the signal controlling relays of the opposing signal 5 is opened to prevent this signal frombeing cleared. The route locking circuit to the relay 4-5LS is opened at the front contact of armature A4T1t as the northbound train enters 3,

When the northbound train has vacated these track sections the track relay LTR and the repeater relay A5TP are reenergized to open the back contacts of armatures 109 and ASTP respectively, with the result that the stick relay 4S and the route locking relay 45LS are returned to their normal condition. The route locking relays-5L8 will function to prevent the false clearing of a signal on the east and west road in the same manner as the relay l-3LS functioned in connection with east and westbound traflic. As relay 4S is picked up the front contact of the armature 48 is closed and the first step of restoring the relay 4-5LS is accomplished, and then when the relay A51? is deenergized and armature A5TP engages its back contact the second step is accomplished and relay e-5LS is restored to its normalcondition. That is to say, the restoring of the route locking relay i -5L8 requires that the track section 4T first be shunted and then the subsequent shunting of the track section A5T. I

Let us next assume that a southbound train enters the approach section A5T when no other train occupies a track section. The deenerglzing of the track repeater relay A5TP completes the circuit to the relay A5I-I and the signal A5 is cleared. As the relay A5TP is deenergized a circuit to the time element device 5TB isclosed at armature 109 and that relay started to function. However, if the southbound train proceeds on south it will be over the crossing 25 before the five minute time period required for the relay 5TE to operate has elapsed and thus under this traflic condition the time element device will have performed no useful function, while the remaining apparatus will have functioned in a manner similar to that described for the other directions of traffic.

Let us now assume that this southbound train enters the section A5T and the signal A5 is cleared,

the route locking rendered effective and the energizing circuit for the time element device 5TB closed the same as mentioned above. The southbound train this time instead of proceeding over the crossing 25 stops and does switching service in the vicinity of the siding c so that it is delayed for a period greater than the five minute interval required for the time element relay 5TE to operate its contacts. At the expiration of the predetermined period the time element relay 5TB causes the armature STE to disengage its back contact to open the circuit to the relay ASH and signal A5 is set at stop. The disengaging of armature A from its back contact prevents the relay 4H from becoming energized to clear the opposing signal 4 should a northbound train enter the section A lT. As the armature 5T3 engages its front contact the circuit to the relay B5B is closed and that relay is energized to clear the special low speed signal B5 and, also, to retain the route locking circuit to the relay 45LS open at the armature 88.

If no train shows up on then when the southbound the east and west road,

train is ready to ad- 1 Vance over the crossing it does so under the signal B5 and the apparatus functions as the southbound train passes over the crossing 25 and through the track section A4T the same as it does for a train not stopped to do switching. Let us assume now that while the southbound train is switching and after the signal B5 has been cleared due to the fact that the predetermined time interval of the time element device 5TE has expired, a train enters either the approach section AlT or A3T of the'east'and west road. This" bound train.

train will cause the signal B5 to be set at stop and the preference taken away from the south- If it is the section AlT that is entered the circuit to the relay B5H is opened at the front contact of armature A1TR As the relay 1351-1 drops an energizing circuit for the route locking relay 4-5LS is closed inasmuch as the time element relay 5TE has lifted the arma ture '107 into engagement with its front contact. This circuit can betraced from positive terminal BL through the back contacts of armatures 88, 89 and 41-1 of relays 35H, A51 1, and 4H, respectively, wire 91, front contact ofarmature 107, wirelOS, winding of relay 4-5LS and to the negative terminal CL. As the relay -45LS picks up, the route locking is released and precedence is taken away from the southbound train. As soon as the route locking is released the circuit to the relay 1H is closed and the signal 1 cleared. From this point on the apparatus will function for the eastbound train that has entered section AlT, the same as previously described. After this eastbound train has passed over the crossing 25 and vacated the section 1T a circuit is closed to the relay 35H that extends from positive terminal BL up to the armature 5TB as was pointed out above and then as armature 5TE now engages its front contact the circuit extends through contact L front contact of armature ls of the stick relay 18 as that relay is closed by the eastbound train entering the section 1T, front contact of armature AlTR and winding of relay B511 to the negative terminal CL. Thus the signal B5 is again cleared for the southbound train and the route locking relay 4-5LS is again deenergized. As the eastbound train moves away fromthe crossing and vacates the section A3T the relay 1351-1 is'retained energized by the circuit through the front contacts of armatures At'llt and AlTR of track relays ASTR and AlTR, respectively. If it pears on the crossing road then the relay 35H is deenergized by the opening of the armature ASTRA and precedence is taken away from the southbound train and the signal 3 cleared for the westbound train. As the westbound train advances over the crossing and vacates the section 1T the relay B5H is reenergized by the circuit through the armature A3TR and the front contact of armature 38 of the'stick relay 38, as that relay is picked up by the westbound train entering section lT.

When the southbound train has finished switch-- its precedence and the signal B5 is retained ener-- gized even though a train on the east and west road should now enter an approach track section. It is to be noted that as the southbound train vacates the section 135T and the track repeater relay A5TP is energized the circuit to the time element device 5TE is opened and its contacts immediately are restored to their original positions. It is also to be noted that the time element device STE cannot function for a northis a westbound train that ap-- rec bound train even though that train should stop to do switching at the siding 0 due to the fact that the stick relay 4S is picked up as the northbound train entered the section 4T and thus the circuit to the relay STE is held open at the armature i Work type.

I intersecting routes are locked out by a route locklocking limits as is given to traflic on the main h enters ,apreliminaryshort eonora The manually controlled time releases'b and a3: will be located near the crossing 25. and may take any one of the many forms well-known in the art, for example, they may be of the clock- The manually controlled time release provided for each road permits the release of the crossing in the event of. a track circuit failure in connection with, any one of the track sections. A failure of the track section AlT would cause signal 1 to be cleared and'the route locking relay 1-3LS deenergized. If now a northbound train desires to proceed over the crossing a member of the crew will operate the release a The operation of the release a first opens the circuits to all,- the signal controlling relays at the contacts 18 and 38 and then as the contact 84 closes, the route locking circuit to the relay 1-3LS is closed and that relay is then retained energized by its stick'circuit. As the timerelease a returns to its normalposition at the end of this movement the contact 38 is made to close slightly ahead of the contact 18 so that the relay will be energized and the signal 4 cleared before the circuit is restored to the signal controlling relays for the east and west road at the contact 18. When relay 4H is energized and the signal 4 cleared the northbound train, can then proceed over the crossing 25 in the usual manner. The manually controlled time release b operates to release the crossing for east and westbound trains where there is a failure of an approach track section of the-north and south road in a manner similar to that just describedfor the release a In connection with the contacts 1? and 37, the contact 17 will be so adjusted as to close slightly ahead of thecontact 37 as the time release 2) returns to its. normal position at the end of an operation. With contact 17 closing ahead of contact 37 then the circuit to the signal controlling relays for the east and west road will be closed and these relays function before the circuit to the relays for the north and south road'is closed.

Therefore, the system here disclosed provides an automatic interlocking wherein the approach of a train causes a signal to be cleared for the trafiic route to be traversed by that train only when no converging route has previously been established. As the train approaches on the established route the signals of all converging or ing circuit. To release this route locking circuit requirestwo subsequent steps. These two steps are accomplished as the train shunts two successivetracksections and thus the route locking cannot be released and a signal cleared for an intersecting route as the result of .a momentary shunting of a track circuit. This system obtains the same route locking protection for movements from a passing siding that ends within the intertrack. Where a train is held for switching, or for other purposes, within the vicinity of the interlocking after the route has been established for that train an automatic time element device cancels the preference established for the train and displays a special low speed signal which can also be cancelled and an intersecting route set up in response to the approach of a train on the opposing road. As soon as the train on the opposing road has proceeded over the intersection the special low speed signal for the first train is again displayed. Precedence for the switching train is fully reestablished" whenever that train track section-showing thereby that it is ready to advance over the inter-.- I section.

Manually controlled time releases locatedin the vicinity of the crossing permit release. of thecrossing in the event or a track circuit failure of one of the approach track ence is established for the road that desires: to use the crossing.

Although I have herein shown and described. only one form of apparatus embodying. my invention, it is understood modifications may be scope of the appended claims from the spirit and Having thus described my invention, what I claim is:

1. In combination, a traffic route, a first signal. to govern traffic over the route under certain traffic conditions, a first normally deenergized-relay to control said signal, a second signal to gov.- ern traffic over the route under certain other trailic conditions, a second normally deenergized relay to control said inactive time element device adapted to function. in a predetermined time interval after its energizing circuit is closed, a track circuit means responsive to a train approaching energize the first relay to clear the first signal and to close the energizing circuit of said time element device, and time element device to deenergize the said first. relay and to energize the second relay to clear the second signal determined time interval.

2. In combination, a trafiic route, a first signal-110: normally at stop to govern traffic over the route under certain traffic conditions, a second signal. normally at stop to govern traffic over the routeunder other traflic conditions, a normally inactive. time element device adapted when energizedv to 115, function in a predetermined time interval, anapproach track section, means responsive toa: train occupyingsaid track section to clearv said first signal and to energize said time element device, and means controlled by the time element 120. device to set the first signal at the second signal at the expiration of said predetermined time interval.

3. In combination, two intersecting railroads, an approach track section section for each road to govern trafiic through its crossingtrack section and each cleared when approach track section, element device associated with one of said rall- 13o. roads and adapted when active to operate in a predetermined time to a train entering the approach track section of the railroad with which vice is associated to render active the time element device and to prevent the clearing of. the signal for the other road, means controlled by the said time element device to set the signal for: its own road at stop and to cancel the control over the signal of the other the predetermined time interval when the train in the approach track section has been delayed for a period greater than the said time interval, and a second signal for the road with which said: time element device is associated to govern the-4.5; delayed train through the crossing tracktsection of that road. I

4. In combination, a first, a second anda third... track section fora railway forming a trafiicroute,

a. second. railway intersecting thev second. trackldflg sections, and preferthat various changes and made therein Within the without departing:- scope of my invention.

second signal, a normally said route to means controlled by said1105 at the expiration of said prestop and to clear;

and a crossing track railroad, a signal for eachrail-- a train enters its a normally inactive time interval, means responsive said time element deroad at the expiration'of;

I railway track enters 3 stick relay energized as for each railway,

..lwhen deenergized to section of the first railway, a route locking circuit so controlled as to prevent a train on the second railway from proceeding over the intersection when a train occupies the first track section, a

the train in the first section advances into the second track section, a track relay controlled by the third track section and a circuit means controlled jointly by said stick relay and said track relay to release the route locking circuit.

5. In combination, two intersecting raiilway tracks, an approach track section for each railway, a route locking circuit for each railway track so controlled as to prevent a train on the opposite track from proceeding over the intersection when a train occupies the approach track section of the track with which said route locking circuit is associated, and circuit means to release a given one of the route locking circuits l when two trains one on each railway enter the approach track sections simultaneously.

6. In combination, two intersecting railway tracks, an approach track section for each railway, a normally energized route locking circuit means to deenergize a route locking circuit to prevent a train on the opposite track from proceeding over the intersection when a train enters the approach track section of the track with which the route locking circuit is associated, and means controlled by a given one of said route locking circuits to release the other route locking circuit when both route locking circuits are simultaneously deenergized.

'7. In combination, a first and a second track section for a railway track, a second railway track intersecting the second track section, a siding track converging into the said second track section, a normally energized route locking circuit for the first mentioned railway track arranged prevent a train on the second mentioned railway track from proceeding over the intersection, and circuit means to deenergize said route locking circuit when a train on the first the first section or when the siding switch is set for trafiic to move from the siding to the second track section.

8. In combination, a stretch of railway, a first and a second approach track section to said stretch, an A signal and a B signal to govern traffic through said stretch, a second railway intersecting said stretch, a normally energized route locking relay for said stretch, means responsive to a train entering the first approach track section to clear the A signal and to deenergize the route locking relay to prevent a train on the second railway from proceeding over the intersection, a time element device to set the A signal at stop, to'reenergize the route locking relay and to clear the B signal when the train has been delayed in the first approach track 'section a predetermined period of time, and means to deenergize the route locking relay when the train enters the second approach track section.

9. In combination; a stretch of railway, a first and a second approach track section to said stretch, an A signal and a B signal to govern trafiic through the stretch, a second railway intersecting the stretch, an approach track section for said second railway, a signal for said second railway to govern traffic over the intersection, a normally energized approach locking relay for the stretch, means responsive to a train entering the first approach track section to clear the A signal and to deenergize relay to prevent the signal on the second'railway the route locking from being cleared; a time element device to set the A signal at stop, to clear the B signal and to reenergize the route locking relay when the train in the first approach section is delayed a predetermined period of time; means responsive to a train entering the approach section of the second railway to set the B signal at stop and to clear the signal on said second railway, and means to hold the B signal at clear and to deenergize the route locking relay when the first mentioned train enters the second approach track section.

10. In combination, a railway having a crossing track section and an approach track section on each side of said crossing track section, a second railway intersecting said crossing track section, a track circuit for each track section, a signal at each end of said crossing section to govern trafiic in opposite directions through said section, a normally energized route locking relay associated with the crossing section adapted when deenergized to prevent a train on the second railway from proceeding over the intersection, means controlled by the track circuit of each approach section to clear the signal adjacent the section and to deenergize the route locking relay a contact of an energizing as the train occupies the opposing approach track section.

11. In combination, twointersecting railways, a signal for each railway to govern trafiic over the intersection, a signal controlling circuit for each signal, an approach track section for each railway adapted to clear the associated signal to advance a train over the intersection as a train enters that section, a route locking circuit for each railway so controlled as to prevent the signal of the opposing railway being cleared when the associated approach track section is occupied, a manually operated time release for each railway each arranged that when operated it first opens the signal controlling circuits, then closes the route locking circuit of then recloses the signal controlling circuits with the circuit for the signal of the associated railway closed slightly ahead of the circuit for the signal of the opposing railway and thereby give precedent to trafiic on the associated railway.

12. In combination, two intersecting railwaytracks, a siding for one of said railways adjacent the intersection of said railway tracks and provided with a switch, a normally energized the opposing railway and route locking circuit for the railway having the siding, a signal to govern trafiic from the siding over the intersection normally ergized when the switch is set for the siding to clear said signal and to deenergize said route I locking circuit, means controlled by the switch to retain said route locking circuit deenergized as long as it remains set for the siding, and means at stop, a relay encontrolled by the route locking circuit arranged to prevent a train on the other railway from'advancing past the intersection when said circuit is deenergized.

" HENRY S. YOUNG. 

